Thread: Thermal knowledge?

It's not advertising, but a response to a comment which is rather biased, especially when given by someone who claims to be an expert.

Although the 30% smaller pixel may be an advantage for resolution under the right circumstances, those being an increase in overall format size, it is also a disadvantage.

Firstly, it is true that when the pixel size is reduced, so is the amount of light, (light, heat, electromagnetic radiation, call it what you like) that falls upon each pixel is reduced by the same ratio. Therefore, though a 30% gain in resolution is achieved, so is a 30% reduction in sensitivity, and therefore for any given lens aperture, the NETD will be increased accordingly. The NETD by the way is one of the critical benchmarks for any thermal IR system. Higher the NETD, the less capable is the unit for detecting the slight differences between objects of similar heat.

Secondly, because the pixels are so much smaller, the overall size of the sensor is also smaller. This means that the magnification increases at the expense of filed-of-view. A small sensor means that a smaller proportion of the lens is used to form the image, and therefore, clarity (resolving power) is compromised. Further more, smaller sensors require shorter focal length lenses to form a usable image.

I remember when I first used large format cameras, the older ones actually had bubbles in the lenses, and yet, the image quality was breathtaking. A 640x480 sensor will piss all over a smaller sensor, regardless of pixel pitch. I know this, because I've seen for myself.

I think it would be really helpful, if we didn't confuse our potential customers with halve-truths, but let them get unbiased opinions. I therefore think it would be really good if Owl Optics and ourselves lend some equipment to forum members so that they can see, try, and form opinions based upon experience.

How about it?